<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <button data-a="10" data-b="20" data-c="30">按钮</button>
  <script>
    var btn = document.querySelector('button');
    // h5 新增自定义数据属性
    console.log(btn.dataset);
  </script>
</body>
</html>